According to 3GPP (The 3rd Generation Partnership Project), Multimedia Broadcast/Multicast Service (MBMS) using a mobile packet network is standardized for a LTE (Long Term Evolution) communication scheme.
According to MBMS, it becomes possible to use at least one of a Unicast/MBMS Mixed Cell utilizing a frequency band that is used also in service other than MBMS, and a MBMS Dedicated Cell utilizing a frequency band exclusively for MBMS.
In the case of the Unicast/MBMS Mixed Cell, as disclosed in Japanese Patent Laying-Open No. 2007-300503 (PTD 1), a subframe for MBMS (Multicast CH (MCH) subframe) and a subframe for unicast are subjected to time-division multiplexing (TDM), thereby transmitting MBMS.
Furthermore, according to 3GPP, the specifications of Long Term Evolution-Advanced (LTE-A) is being under study. In LTE-A, it is required to implement higher-speed communication than LTE. Accordingly, in LTE-A, it is required to support a band wider than that in LTE (a band up to 100 MHz exceeding the 20-MHz band in LTE). It is however difficult to ensure a globally-continuous wide-band frequency domain for LTE-A.
Therefore, a career aggregation (CA) technique is under study for LTE-A for the purpose of maintaining the compatibility with LTE as much as possible. The carrier aggregation technique is for establishing communication collectively on a plurality of frequency bands each having a bandwidth referred to as a component carrier (CC) up to 20 MHz, thereby ensuring the bandwidth up to 100 MHz, so as to implement high-speed and large-capacity communication. Non-Patent Document 1 set forth below discloses carrier aggregation described above.